Biological Warfare Agents

The Biological Warfare (BW) agent is a greater and more likely mail threat due to the small amount of agents required, the long duration between exposure and symptoms and the relatively low cost to produce. The letter has a greater chance of reaching its destination before anyone exposed starts to show symptoms. Exposure to the BW agent will result in serious heath problems or death if left untreated. For the majority of us, being the target of a letter tainted with a BW agent should not be a concern. The larger threats are hoaxes or cross-contamination of trace amounts of the BW agent from another letter intended for a high-threat target. For higher risk targets such as government agencies, defense contractors, news organizations and financial institutions, the threat has already proven to be real. The defense against a letter tainted with a BW agent includes physical security, detection, containment and decontamination.


Facility Security

Standard physical security methods used to minimize postal theft and the protection of company-sensitive correspondence are the first lines of defense. Even if you assess that your facility is not a high-risk target for terrorism, these are classical physical security tips that apply to everyone at some level. The mail center should be off-limits to non-mail center personnel. Everyone authorized to work in the mail center should be easily identifiable. Surveillance of mail center operations by security or mail center supervisors will help deter suspicious activity. Surveillance can either be through line-of-sight or closed-circuit monitoring. Employees must be screened as well as trained in mail center security and all mail screening procedures and response plans. Direct access to the mail center from receiving areas such as the loading dock or windows needs to be secured. This would be equivalent to leaving the front door open to anyone who wants to walk in unchecked.


There should be a mail staging area between the loading dock and the mail center where visual prescreening of mail and packages can be performed. Mail should not be received at the main lobby. This only allows a suspicious letter or package to circumvent the mail screening process. Once the physical security is in place, the next step is incorporating screening for chemical and biological agents and explosives.



Biological Detection test methods can be time consuming and should be considered when selecting equipment. Testing could have very negative impact on the mail flow. The mail should not leave the containment area until testing has been completed. Rapid detection is required in order to contain the BW agent and treat those exposed.


The technology of choice for biological detection is Polymerase Chain Reaction (PCR). PCR is a laboratory technology that is moving into the field to fight BW terrorism. The chemistry behind PCR is complicated, but in layman's terms, PCR can replicate very small amounts of DNA from the BW agent many times so that the DNA sequence can be identified. Commercially available, rapid PCR systems are able to amplify and identify known DNA sequences within 30 to 35 minutes. The methods for collecting the test sample can vary based on the type of mail sorting equipment currently used in your mail center. For high-volume mail centers, your current mail sorting systems may be modified to add an air collection sample preparation system. The objective is not to impede the flow of the mail. For low-volume mail centers, there are new commercially available mail sorting systems for BW agent screening, such as the Smiths Detection Mail Sentry. Make sure that the system selected can support your projected daily volume of mail. PCR technology does require test consumables that will add to your daily operating costs.



Containment of the BW agent to the mail center is key to avoiding contamination of the entire facility. For larger corporations, the mail screening facility should be remotely located off-site for the ultimate separation and containment. For small facilities where the mail center cannot be remotely located, a containment capability has to be built into the mail center. The mail center itself should minimize open access to other public areas. The mail center needs to be kept at negative air pressure with respect to the rest of the facility and use High Efficiency Particulate Air (HEPA) filters in all HVAC returns. This is to prevent the BW · agent from escaping through open doors and windows and contaminating the rest of the facility through the HVAC system. Ideally, the HVAC system for the mail center should be a completely separate system from that of the main facility. A small containment area within the mail center should be established for suspicious letters or packages. For smaller facilities or offices that do not have a designated mail center, a closed off, secured area should be assigned where the mail can be sorted and inspected. Low-volume mail sorting systems with BW detection, built in HEPA filters and a containment box for suspicious letters and packages may be the right choice.



Decontamination protocols need to be in place as part of the overall response planning to a tainted letter or package. If containment efforts are adequate, then decontamination will be isolated to the mail center. The method for decontamination of biological agents is to seal off the contaminated area and fill the area with Chlorine Dioxide gas. Failure in containment may require the entire facility to be decontaminated. Personal decontamination begins with adequate protection. For very high-threat targets, the mail center workers may be dressed in protective suits. For low-threat targets, minimizing exposed skin and wearing standard gloves and dust masks can reduce the risk of exposure. Symptoms from BW agent exposure are slow to appear. For example, the incubation period for Anthrax is one to seven days and treatment is available if identified early enough. Therefore, rapid detection is the key to minimizing the time between exposure and treatment. Ideally, a decontamination area for people exposed should be incorporated into the mail center design. If a decontamination area is not available, exposed personnel should be isolated from the main facility until help arrives.


Training and Response Planning

Mail handlers should be trained in identifying suspicious letters and packaging as well as response plans. Response planning must include emergency contact information for local first responders. Security personnel have now taken on the roll of the first responder. They are the first to receive the call to investigate a suspicious material either in the mail center or elsewhere in the facility. Having this responsibility, the security personnel need to be equipped with similar hand-held chemical, biological and explosive detection equipment used by many emergency first responders. This will allow the suspect material to be quickly identified on location as either a hoax or a genuine threat. In both cases, rapid detection is essential to resuming work as usual or containing the threat. The first responder type detectors may also be used as part of the day-to-day screening operation in the mail center.


Prepare to Scale

Mail center security is no different than restricting access and monitoring activities in any other area of the facility. Professional assistance may be required to perform vulnerability assessments and make suggestions on building protection and detection technologies suitable to counter identified threats. Through this process, keep in mind to scale this effort to the threat and to minimize the disruption to day-to-day operations and the flow of the mail. As a final thought, the threat is real, the probability of the threat is low, the probability of a hoax is higher, and the level of security screening should be scaled to the level of the threat.


David Karmel is director of Commercial Products at Smiths Detection. Karmel oversees the development of mail screening products that detect biological warfare agents, as well as handheld chemical and biological detectors for military and security personnel and emergency first responders. Smiths Detection is the leading provider of chemical, biological and explosive detectors and x-ray systems. For additional information, please contact Susan Cooper at 973-830-2131 or visit